Improvement in elevating-jacks



UNITED STATES VPATENT OFFICE.

SAMUEL LAUOHLI, OF ST.l LOUIS, MISSOURI, ASSIGNOR IO HIMSELF AND WILLIAMG. RICH, OF SAME PLAGE.

IMPROVEMENT IN ELEVATI NGJACKS.

Specification forming part of Letters Patent No. 43,369, dated June 28,1864.

To all whom, it may concern:

Be it known that I, SAMUEL LAUGHLI, of St. Louis, in the county of St.Louis and State of Missouri, have invented a new and useful Improvementin Elevating-Jacks; and I do hereby declare that the following is afull, clear, and exact description thereof, which will enable othersskilled in the art to make and use the same, reference being had to theaccompanying drawings, forming part of this specification, in which-Figure l represents a side sectional elevation of my invention; Fig. 2,a plan sectional view of the same; Fig. 3, a plan of the doubleeccentric-shaft; Fig. 4, an end view of the same.

Similar letters of reference indicate like parts.

This invention pertains to that class of devices commonlyknown as jacks,or machines used for the movement of all kinds of weighty bodies.

A is the post or standard upon which the parts are mounted. Thispostma-y be made of wood, iron, or other material, in one or more partsand in any desired form.

B is an aperture extending through the standard A, said aperturecorresponding in area and form to a toothed bar, C, which moves in saidaperture. The bar C is furnished at its upper end with a pivoted plateor head, ci, upon which rests the object to be raised, lowered, ormoved.

Within a cavity, Bf, in the standard A, at one side of the toothed barC, I arrange a rotating-shaft, D, which passes through the standard A,and has one or both of its ends squared and made to project from thestandard A, to receive a crank, D', by which the shaft D and the machineis operated. Two cranks may be employed, if desired, one upon each endof the shaft D.

Arranged upon, or forming part ofthe shaft D, are two cams oreccentrios, E E', having their thrusts arranged on opposite sides of theshaft D. Upon each cam E E there is fitted a swinging double-armed leverF F in the manner shown. The extremities ofthe lever-arms terminate inteeth b b, which gear or take into the teeth of the toothed bar (l. Eachlever F F is so hung upon the cams E E that the lever-arms are ofunequal length. Behind each lever there is a spring, Gr, arranged asshown, each spring having two leaves, one of which presses on eachleverarm. Vhen the shaft D is turned, the eccentrics E E will impart totheir respective 1evers F F a combined vertical and horizontal movement,and the teeth b b of the said levers will alternately engage the teethof the bar U. The cams E E are so made and set that a vertical movementof the levers F F will take place while the teeth b b are engaged withthe teeth of the bar C, by which vertical movement the bar C will beraised or lowered accordin g to the direction in which the shaft D isturned. The arrangement of the cams E E is also such that the movementof the levers F F is alternate in respect to their engagement ordisengagement from bar C. The several teeth b b of each lever act alsoalter nately upon the teeth of the bar C. When the bar U is being movedupward, the upper tooth, b, does not withdraw from the teeth of bar Cuntil after the lower tooth, b', has bc en withdrawn. When the bar C ismoved downward, the lower tooth, b', remains in contact with the teethof bar C until after the upper tooth, b, has withdrawn. Completesecurity against any slippage of the bar C is thus secured.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- The combination of the double eccentricshaft D andindependent alternating levers E E with the rack-bar U, substantially inthe manner and for the purpose herein shown and described.

SAMUEL LAUCHLI.

